Wednesday, September 28, 2011

Camera Lenses 101: Kit Lenses

The Nikkor 18-55 AF-S VR: the epitome of the modern kit lens in taht it is a zoom with decent optics, modern features, but questionable build quality.
When many people think about buying a camera, surprisingly, they never really consider the lens, the very part that focuses the incoming light in order to create a picture. Fortunately (or perhaps not), camera makers often cover this oversight when packaging their cameras, especially the low to mid-level models, for market.

Way back when, as in the early 1980s and before, camera makers didn't skimp on bundled glass. Example, my Canon FTQL came with a 50 f1.8 optic as standard. Now the funny part: this “cheap” lens is better built than all but the most expensive of today's lenses and, on top of that, it takes good pictures. Stop it down and the corners are good, too. Yes, there were better lenses at the time but, by and large, the kit optics were no slouches, either.

Now, enter the zoom lens revolution.

Before the mid 1980s, zoom lenses were something that no serious photographer could be caught dead with. Why? As in the infancy of any given technology, the products were not all that good. For the first part of their existence, zooms offered flexibility at a lost of lousy optics. Result: serious photographers stuck with primes. However, by the middle 1980s, the zoom lens was maturing into a capable photographic tool at the same time that AF cameras were taking the photographic world by storm. By the end of the 80s, many people who would not have attempted photography otherwise, thanks to the convenience of AF, were snapping pictures. Obviously, people who get into photography because of a technological advance that makes the whole process easier are going to want convenience, and thus zoom lenses.

So, to satisfy the need of these beginning, convenience-orientated photographers, manufacturers stopped equipping their camera kits with “cheap” primes made of metal and containing good optics with cheap plastic zooms containing passable optics and sometimes second-rate AF mechanisms. Why? The public (actually, the influx of convenience-craving photographers) demanded it. AS for the high-end cameras, the manufacturers started selling them without lenses as the people who bought such models would know what lenses they wanted anyway (if they didn't own them already). So, in no time at all, the kit lens became synonymous with junk.

So, in 2011, is this still the case?

Fortunately, no. The great thing about a free market is that the consumer rules so, if people stop buying a product they consider of shoddy craftsmanship, the manufacturers will listen and make a better product. Case in point: the evolution from the kit lens from plastic, anything but fantastic, to a true, albeit still somewhat limited, photographic tool.

Right now, kit zooms are offering features that, even just a few years ago, would have seemed unthinkable. Fancy optics in the form of aspheric elements, low dispersion glass, and even coatings now come as standard on many kit lenses by many different manufacturers. Right now, Nikon offers sonic drive AF on its $200 18-55 kit model. Last year, Pentax came out with sub $250 lenses with rubber gaskets at the mount to protect against dust and moisture. Both Canon and Nikon (the big holdouts against in-body stabilization) both offer sub $200 lenses with stabilizers rated up to 4 stops effective. On top of all this, the optics themselves are getting better, with some lenses, at least at some of their focal settings, offering image quality comparable to much more expensive, pro-grade zooms.

Now, the big question may be, with all these pluses of kit zooms, why not just stick with them in the first place?

Well, some things don't seem to be changing anytime soon. Then as now, the build quality of kit zooms (apart from the weather-resistant Pentax lenses) is terrible. How shoddily are some of these lenses built? A few models don't even have metal mounts! An often cut ergonomic corner is that most kit zooms don't have a true manual focus ring. Instead, one has to turn the end of the lens itself for MF. AF mechanisms? Still often inferior to higher-grade models in that AF is slower and/or doesn't allow full time manual override. As a last note, to keep prices down, the apertures are still slow, typically in the f3.5-5.6 range.

Now, examination complete, when you buy a camera with a bundled lens, should you keep it or try to unload it on Craigslist or Ebay?

Answer: it's all about what you shoot. For most situations, I would say that the kit lenses are just fine. The only real situation where the stock kit lens falls flat is under low-light conditions where the slow apertures pretty much require using flash, which is not always desirable (or even allowed at some public venues). The good news is that the advent of image stabilization (whether in-body or in-lens) will offset this disadvantage if the subject is stationary, which makes such lenses great for nightscapes. Unfortunately, image stabilization does nothing to freeze action, only aperture can do that. My key to lens buying:

Action = aperture
Stationary = stabilizer

Basically, if you're shooting stationary subjects, just stick with the kit lens, it will do the job just fine in most situations. If action/low light photography is your thing, it may be a good idea to invest in a fast (f2 or faster, preferably) prime instead.

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